Homeland Security Secretary Jeh Johnson says the only way unaccompanied immigrant children will be allowed to stay in the U.S. is if they can find a parent in the country. / AP

by Jarrad Saffren, USA TODAY

by Jarrad Saffren, USA TODAY

WASHINGTON - The only way unaccompanied immigrant children in the United States will be allowed to stay here is if they can find a parent in the country, Homeland Security Jeh Johnson suggested in a news conference Thursday.

"The law requires that we act in the best interests of the child," said Johnson in a news conference. "Often that means reuniting the child with parents or family in the U.S."

Johnson spoke as the number of unaccompanied immigrant children being held in federal detention facilities is growing. Earlier this week, federal officials estimated that at least 1,000 children would be sent to a makeshift way station set up in a Border Patrol detention facility in Nogales, Ariz.

More than 47,000 unaccompanied child migrants have crossed the border in 2014, Johnson said. Most in the Nogales facility are from either Honduras, Guatemala, or El Salvador. Since these countries don't border the United States, the federal government cannot deport the kids right away. They must be turned over to HHS after three days.

HHS must provide adequate housing, food and health care for the children, Johnson said, while the department looks for family members living in the United States who can take them in. Federal law gives Hondurans and Salvadorans temporary protected status in the United States, meaning they can work here but not stay permanently.

The laws will not encourage more children to cross the border, Johnson said, because "they won't get a path to citizenship and it's not safe for children to be in the hands of smugglers."

Johnson said the number of unaccompanied children makes a comprehensive immigration bill more necessary.

"We need immigration reform because it includes money for better border security," he said. "And we need better border security."

By year's end, 70,000 to 90,000 unaccompanied children are expected to cross the border compared to only 24,000 in 2013. The U.S. government has spent more than $126 billion over the past nine years on border security and enforcement. But most of that money has been put toward areas in California, Arizona, and West Texas. This year's migrants are entering mostly through the Rio Grande Valley in South Texas.